Gate-operating mechanism.



G. B. VARNUM. GATE OPERATING MECHANISM. APPLICATloN FILED APR. la. 191s.

'Patented '0016. 24. 1916.

" lexertion on the part of the attendant.

i a citizen of the United States,- residing at' imi, s

@WENT orion.

GEORGE Bi VARNUM, 0F LOS ANGELES, CALIFORNIA.

GATE-OPERATING MEcHAi-visivi.

To all 'whom 'it may concern:

Be it' known that I, GEORGE B.- VARNUM,

Los Angeles, in the county of Los Angeles, State of California, have invented new and useful. Improvementsl in Gate-Operating Mechanism, of which the ,following is al i specilication.

This invention relates to mechanism for operating gates, and particularly for sliding or rolling gatessuch as are used in banks, jails and the like; and the invention consists particularly in the provision of a simple and efficient means for easily, quickly and noiselessly handling heavy gates Without -The details of my invention are fully described in the following specification. a

For the purpose of this specification I have illustrated in the accompanying drawings a preferred and specific form of mechanism embodying my invention; but it will be understood that many variations in construction and operation may be made without departing from my invention, and also that my invention is notlimited lin itsuse to the particular class of gates shown in the drawings, being useful for operating gates `regardless of their class orof their manner of movement.

In the accompanying drawings Figure .1*

is an elevation showing my mechanism as it .appearsin use, Fig. 2 is a view showing a section of the operating mechanism and also showing diagrammatieally the electrical control system therefor, Fig. 3 is a section taken as indicated by line 3 3 of Fig. 1, and Fig. L1 is a detail' showing a modified construction.

'In the drawings I have showny a typical installation of my improved. operating mechanism. I illustrate a bank grille 10 of any usual typehaving a gate 11 4hung on rollers 12 which run on a horizontal way 13.

.Gates of this type vare usually very heavy,

I' and an excessive exertion is required of the attendant in order to. manually open and close them with 'any celerity.

Itis a particular object of this invention to provide a simple mechanism which, under Specification of Letters Patent. I

Patented Oct.' 24, 1916.

. Application led April 19, 1915. Serial N o. 22,350.

complete control of the attendant, will automatically open and close such a gate'. I prefer, in gates of the general class illustrated herein, to have a mechanism, which,

once set in operationwill automatically open and then automatically close the gate; but the mechanism may be varied, as is hereinafter explained, so that both the opening and the closing movement must be started bymanual action of the attendant.

In the preferred forni of mechanism, illustrated herein, I utilize a pair of links 15 and 16, which links are pivoted together at 17 and the end Vof one link is pivoted at 18 to the gate While the end of the other link is pivotedat 19 to a small bracket 20 mounted upon the stationary part of 'the grille. In the normal closed position of the gate they tWo links 15 and 16 are made to extend in a straight line; so that very little force is required to keep the links in a straight line and to thus prevent gate 11 being forced open. My operating mechanism is so donstituted that these links l5 and 16 are rigidly held in theiry straight line positions, so that the gate 11 is securely locked in closed position. The mechanism which causes the movement of the Ilinks 15 and 16 is now described.

I employ an electric motor 25 of suitable power, Isaid motor driving a worm 26 meshing with a worm wheel 27 mounted upon Astu'd shaft 28. A crank pin 29fis carried tion stated it will be seen that this crank and the connecting rod are on a straight line. Any pressure longitudinally on the connecting rod 30 will thus have no effect (or very little efi'ect,vif the crank and connecting rod are slightly out of line) to rotatevtheworin iooy wheel 27; yand in any'case, any pressurey which may be brought to bear tending to rocause the worm wheel 26 to jrotate, the pitch of the worm 26 being such that-'the gear train formed by the worm 26 and the worm wheel 27 is incapable of being moved by back pressure exerted through the worm wheel 27. i

The foregoing described parts a particular feature of my invention.

constitute It will be noted that these-operating parts are.

simple in their nature and intheir combination; yet the arrangement is such that .it is practically impossible \to force the gate 11 open when the mechanism is in its norf` A feature of my invention which I wish ,Ito particularly emphasize is the electrical Icontrol thereof. The worm wheel '27 carries a cam disk 31 which'may have one or more notches 32 in its periphery, the periphery of the disk being followed by a small roller follower `33 on a'switch arm, 34`pivotedf`at 35.. andjpressed into engage'- ment with the cam by the spring 36. A stationary contact 37 is adaptedto be en- Agaged by the switch arm 34 when the switch .arm is pressed back away from the cam disk 31.l lVhen the roller 33 enters one of the notches 32 the circuit is broken between the switch arm 34 and the stationary contact I l holding it open. A wire 46 leads back to the other feed wire 40a.

motor to a hand operated switch 44 which switch preferably has a spring 45 normally other side of the-electrical source, to the A wire 47 connects with wire 43 and leads to the stationary contact 37, while a wire 48 connects between the switch arm 34 and the. feed wire 40a. It will be seen that the switch 44 and the cam operatedswitch are arranged in parallel with each other. .f

f The k,attendant momentarily tate the worm wheel cannot be sufficient to'l The case 9 con! The operation of .the device is as follows: closes the switch 44, thus supplying current to the motor which starts the rotation of the parts in the direction indicated in the Fig. 2.

" Immediately the rotation starts the switch arm 34 is thrown to the left in Fig. 2, and the circuit to the motor is closed at the contact 37. The attendant can then .release the switch 44, and the subsequent operation of the gate will take place automatically without care onI the part of the attendant. The motor continues to operate and to re- .Volve the parts in the direction indicated about theshaft 28 a'd tli'e gate 11 will con-V sequently be held in open position. However, for some installations, and particularly for bank installations, I prefer to have only one notch 32 in the disk 31, which will cause vthe automatic and continuous operation of the mechanism until the crank pin 29 has made a complete revolution, causing the gate` 11 to be automatically opened 'and immediately automatically closed. The notches 32 are made sufficiently long to allow a slight overrun by the motor 25 after current iscut off, without again pushing the' switch arm 34 outwardly and again clos y `ing the circuit. i The exact length of` the notchV depends upon how far the motor 25 will run after current is cut off. It will be noted .that the swing of the connecting rod 30 is'such as to give it greater leverage 'on the link 16. Thus, when the opening operation'is just commencing, the upper endof theV connecting rod 30 swings toward` the right in Figs. 1 and 2, so thatthe pull through the connecting rod 30 becomes more nearly Vat right angles to the line through pivots 19 and3l; and that, simi-'- necting rod 30 is'then traveling to the left 'i in Fig. 1, tending to make said angle again as nearly as possible aright angle. It will be noticed the opening and Vclosing move- .ments of the gate are very gradually and easily begun. Gates of the character illustrated are usually very heavy, butfare hung on bearings of a character which allows them to move with minimum friction. These gates move very easily after they are once started.-v

It is a feature of my invention that Iuti-A lize very little power for moving the gate. I needvery little .power for starting the movement of the gate, as it will be seen that the gate is very gradually accelerated both Lacanau at the start of the opening and of the closing movements. This is due to the particular arrangement of the parts as hereinbefore described, to the fact that when the links 15 and 16 are on a straight line the crank (hereinbefore referred to) is also on any obstruction Awill immediately cause the poses whole operation f to cease. Thus, in bank grilles, where the operation is preferably automaticior bothv opening and closing, should any personv bev caught in the gate the closing operation would immediately cease. The switch 4l also provides means under control of the attendant for stopping the operation oi the gate at any desired point.

It will be noted that the links and. 16.. move downwardly during the opening movement ot the gate; and the weightof the links assists the motor in opening the gate. When the ga s is closing the weight of the links opie motor. The result is that the gate oper comparatively quickly and closes comparatively slowly. As shown in Fig. Il, I may make a slot 3la for the reception of pin 3l in the connecting rod so that there may be an ap. ciable lost motion at the upper and lower; ends ot the stroke. Thus, on the downward. strokel vof the connecting rod,v

when opening the gate, the pin is at the upper end of the slot; and when the lowermost point is reached by the connecting rod 'the gate will stand open an appreciable time while the connecting rod moves upwardly untilv the lower end of the slot moves up under the pin. i'

Having described a preferred form of my invention, l claim l. Grate operating mechanism, embodying a stationary frame, a horizontally movable gate, a pair of links pivoted one at one end to the gate` the other at one end to the stationary frame, the other two ends of said links being pivotally connected together, all

of said pivotal points being normallyA approximately on a straight line, and means to. vmove the second mentionedv link about its stationary pivot embodying a crank and connecting rod between the crank and said link, said connecting rod and crank being normally on a straight line `when the two links are-on a straight line, a worm wheel connected with the crank, a worm meshing with said worin wheel, a motor driving said worm, a cam disk on said worm wheel, and electrical control means embodying a circuit including the motor, a hand operated switch in said circuit, and a cam operated switch embodying a stationary contact and a movable arm, a spring to throw they arm away from the stationary Contact and toward said cam, and a cam' follower on saidarm, said .cam operated switch being arranged in said circuit in parallel with the hand operatedswitch.' v

2.' Gate operating mechanism, embodying a stationary frame, a horizontally movable.

gate, a pair of links pivoted one at one end to the gate, the other at one end to the stationary frame, the other two ends of said links being pivotally connected together, all of said pivotal points being normally approXimately on a straight line, and means to move the second mentioned link about its 'stationary pivot embodying a crank and connecting rod between the crank and said link, said connecting rod and crank being. normally on asti-aight line when the two links are on a straight line, a worm wheel connected with the crank, a worm meshing with said'` worm wheel, a motor driving said worm, and'electrical control means for the motor embodying ai circuit including the motor, a hand operated switch in said cir cuit, and an automatic switch in said lcircuit in parallel with said hand operated switch,

said automatic switch being operated from theworm wheel. Y

3. Gate operating mechanism, embodying 'a' stationary frame, a horizontally movable gate, a pair of normally horizontal links pivoted one at one end to the gate, the other l at one end to the frame, the other two ends i of said linksjbeing pivotally connected together, all of said pivotal points being nor-` mally approximately on a straight line, and means to move the second mentioned linkabout -its stationary pivot vembodying a crank and a connecting rod extending vertiino callyfrom the crank to the link, the connection between the rod and link allowing a limited lost motion between those parts for the purpose described, said connecting rod and crank being normally on a straight line when the links are on a straight line, and means to rotate the crank to cause operation as described.-

el. Gate operating mechanismfembodying a stationary frame, a gate movable thereon, a pair of links pivoted one at one end to the gate, the other at one end to the stationary frame, the other two ends of the links being pivotally connected together, all of said pivotal pointsfbeing normally in anv approXimately straight line, and means to oscillate the second mentioned link about its stationary pivot, said meansl embodying a motor, a worm driven by the motor, a worin wheel driven by the worm, connecting means between the worm wheel and the second mentioned link, and electrical control means vfor the motor embodying a circuit includ- In witness that I claim the foregoing I have hereunto subsoribed my name this 12th day of Apr., 1915. y

GEO. B. VARNUM.

ing the motor, a. hand operated vswitch adapted to close the circuit to the motor, and means operated by the Worm Wheel .for opening the circuit after a pre-determined movement of the Worm wheel and When the links are in normal :dined position.

itnesses JAMES T. BARKELEW, ELwooD H. BARKELEW. 

